持久稳定的固态锂电池有突破了

Long-lasting, quick-charging batteries are essential to the expansion of the electric vehicle market, but today's lithium-ion batteries fall short of what's needed -- they're too heavy, too expensive and take too long to charge.

持久、快速充电的电池对电动汽车市场的扩张至关重要，但如今的锂离子电池还不能满足需要——它们太重、太贵、充电时间太长。

For decades, researchers have tried to harness the potential of solid-state, lithium-metal batteries, which hold substantially more energy in the same volume and charge in a fraction of the time compared to traditional lithium-ion batteries.

几十年来，研究人员一直试图利用固态锂金属电池的潜力，与传统的锂离子电池相比，固态锂金属电池在相同体积下能储存更多的能量，充电时间更短。

"A lithium-metal battery is considered the holy grail for battery chemistry because of its high capacity and energy density," said Xin Li, Associate Professor of Materials Science at the Harvard John A. Paulson School of Engineering and Applied Science (SEAS). "But the stability of these batteries has always been poor."

“锂金属电池因其高容量和高能量密度而被认为是电池化学的圣杯，但它们的稳定性一直很差。”哈佛大学SEAS学院材料科学副教授李鑫(Xin Li)表示。

Now, Li and his team have designed a stable, lithium-metal solid state battery that can be charged and discharged at least 10,000 times -- far more cycles than have been previously demonstrated --- at a high current density. The researchers paired the new design with a commercial high energy density cathode material.

近日，李鑫和他的团队设计了一种稳定的锂金属固态电池，可以在高电流密度下进行至少10000次充放电，远超之前演示的循环次数。研究人员将这种新设计与一种商用的高能量密度阴极材料配对。

This battery technology could increase the lifetime of electric vehicles to that of the gasoline cars -- 10 to 15 years -- without the need to replace the battery. With its high current density, the battery could pave the way for electric vehicles that can fully charge within 10 to 20 minutes.

这种电池技术可以将电动汽车的寿命延长至汽油汽车的寿命——10至15年，而无需更换电池。由于其高电流密度，该电池可以在10-20分钟内为电动汽车充满电。The research is published in Nature.

这项研究发表在《自然》杂志上。

The big challenge with lithium-metal batteries has always been chemistry. Lithium batteries move lithium ions from the cathode to the anode during charging. When the anode is made of lithium metal, needle-like structures called dendrites form on the surface. These structures grow like roots into the electrolyte and pierce the barrier separating the anode and cathode, causing the battery to short or even catch fire.

锂金属电池的最大挑战一直是化学。锂电池在充电过程中将锂离子从阴极转移到阳极。当阳极由金属锂制成时，表面形成针状结构，称为枝晶(dendrites)。这些结构像根一样生长在电解液中，刺穿分隔阳极和阴极的屏障，导致电池短路甚至起火。

To overcome this challenge, Li and his team designed a multilayer battery that sandwiches different materials of varying stabilities between the anode and cathode. This multilayer, multimaterial battery prevents the penetration of lithium dendrites not by stopping them altogether but rather by controlling and containing them.

为了克服这一挑战，李和他的团队设计了一种多层电池，在阳极和阴极之间夹有不同稳定性的不同材料。这种多层、多材料电池不是完全阻止锂枝晶，而是通过控制和容纳它们来防止锂枝晶的渗透。

Think of the battery like a BLT sandwich. First comes the bread -- the lithium metal anode -- followed by lettuce -- a coating of graphite. Next, a layer of tomatoes -- the first electrolyte -- and a layer of bacon -- the second electrolyte. Finish it off with another layer of tomatoes and the last piece of bread -- the cathode.

你可以把电池想象成一个三明治：首先是“面包”(锂金属阳极)，然后是“生菜”(一层石墨)。接下来，夹一层“西红柿”(第一种电解质)、一层“培根”(第二种电解质)。最后再来一层“西红柿”和最后一块面包——阴极。

The research was supported by Dean's Competitive Fund for Promising Scholarship at Harvard University and Harvard Data Science Initiative Competitive Research Fund. Further developments of this project will be supported by Harvard Physical Sciences and Engineering Accelerator Award and Harvard Climate Change Solutions Fund.

这项研究得到了哈佛大学院长奖学金竞争基金和哈佛数据科学倡议竞争研究基金的支持。该项目的进一步发展将得到哈佛物理科学与工程加速器奖和哈佛气候变化解决方案基金的支持。